The present invention relates to fillers, elastomeric compositions or composites, and methods to make the same, and methods to improve one or more properties in elastomeric compositions. More specifically, the present invention relates to modified fillers and the use of these fillers in elastomeric compositions.
Carbon blacks and other fillers have been utilized as pigments, fillers, and/or reinforcing agents in the compounding and preparation of compositions used in rubber, plastic, paper or textile applications. The properties of the carbon black or other fillers are important factors in determining various performance characteristics of these compositions.
Much effort has been expended over the last several decades to modify the surface chemistry of carbon black. Useful processes for attaching an organic group to carbon black and uses of the resulting product are described, for example, in U.S. Pat. Nos. 5,559,169; 5,900,029; 5,851,280; 6,042,643; 6,494,946; 6,740,151; and 7,294,185, all of which are incorporated herein by reference in their entirety. U.S. Pat. No. 5,559,169, for example, discloses a carbon black product having an attached organic group of the formula —Ar—Sn—Ar′— or —Ar—Sn—Ar″— (where Ar and Ar′ are arylene groups, Ar″ is an aryl group and n is 1 to 8) that can be employed in ethylene-propylene-diene monomers (EPDM), partially hydrogenated copolymer of acrylonitrile and butadiene (HNBR), or butyl rubber compositions.
Important uses of elastomeric compositions relate to the manufacture of tires and additional ingredients often are added to impart specific properties to the finished product or its components. U.S. Pat. No. 6,014,998, for example, describes the use of benzotriazole or tolyltriazole to improve cure rates, cure efficiency, hardness, static and dynamic moduli, without adversely affecting hysteresis in silica-reinforced rubber compositions for tire components. These compositions include from about 2 to about 35 parts triazoles (preferably from about 2 to about 6 parts triazoles) per hundred parts of rubber. In some cases, brass powder and conductive carbon black are also added and the compositions are mixed by conventional means in one or multiple steps.
U.S. Pat. No. 6,758,891 relates to the treatment of carbon black, graphite powder, graphite fibers, carbon fibers, carbon fibrils, carbon nanotubes, carbon fabrics, glass-like carbon products and active carbon by the reaction with triazene modifying agents. The resulting carbon can be used in rubber, plastics, printing inks, inks, inkjet inks, lacquers, toners and colorants, bitumen, concrete, other constructional materials, and paper.
As indicated above, fillers can provide reinforcing benefits to a variety of materials, including elastomeric compositions. Besides the conventional filler attributes, there is a desire to provide fillers which can improve one or more elastomeric properties, especially hysteresis and/or abrasion resistance. However, in the past, with some elastomeric compositions using fillers, a filler can typically improve one property, but to the detriment of the other property. For instance, while hysteresis may improve, abrasion resistance can decrease or have no improvement. Thus, there is a need to provide fillers which preferably can enhance one of these properties without any significant detriment to the other. Even more preferable would be a filler that can improve both properties, namely improve hysteresis and improve abrasion resistance.